Daylight, as used in connection with the present invention, includes all forms of sunlight whether direct or filtered through clouds or other meteorological phenomena. The amount of daylight available is particularly high on clear, sunny days but is also more than sufficient for interior illumination even on cloudy days when efficient devices are used to transmit daylight into the building.
There are many benefits to using daylight for illuminating areas within enclosed structures such as buildings. The use of daylight over artificial illumination for interior illumination provides a more balanced color rendering of objects which is more aesthetically pleasant and also reduces the need for energy to illuminate the interior of the building artificially. An additional benefit is the reduced amount of radiant energy produced by artificial illumination sources which can, in turn, reduce the amount of cooling needed to maintain a comfortable temperature within a building.
Known systems for transmitting daylight into the interior buildings include skylights and windows. The systems typically sacrifice efficiency or uniform distribution. They are not capable of both efficiently collecting daylight and uniformly transmitting it into the interior of the building. In addition, many of the systems are notorious for heat loss during cool weather and heat gain during warmer weather, both of which are not desired.
Furthermore, the systems typically do not compensate for the position of the sun in the sky and, as a result, transmit varying levels of daylight into the building at different times during each day, as well as differently during each season of the year. In many cases, the amount and quality of light transmitted by the systems is not suitable for interior illumination.
To enhance uniformity of distribution, many skylight designs incorporate diffusing panels or materials which scatter daylight in a disorganized fashion. That disorganized scattering results in illumination which is not particularly sharp.
Attempts have been made to provide more efficient devices for transmitting daylight into the interior of buildings. Solar tracking devices have been used which require mechanical tracking systems to follow the sun's apparent motion across the sky. Such systems are, however, expensive and difficult to maintain, resulting in limited use.